Instrument lighting cover panel



INSTRUMENT LIGHTING COVER PANEL Filed March 2, 1950 24 a5 3/ as 29/n/r//u\ w 1 34 43 I F IG. 4

a as 45 47 zlrwlm bow 53 5/ JOHN M. ROPE THOMAS 0 T W/ST Patented Mar.30, 1954 OF E 2573,92 1 INSTRUMENT LIGHTING COVER PANEL John M. ARoper,Washington, D. ,C.,:and Thomas 0. Twist, Chevy Chase, Md.

Application March 2, 1950, Serial No. 147,311

'13 Claims.

(01. 240-.8.16) (Granted under Title 35,

U. s. Code (1952).

see. 266) The present invention relates to an instrument lightingsystem, and more particularlyto an instrument lighting system for use invehicular instrument panels.

It has been the general practice in the prior art to employ a singlecover panel hand tailored for .all instrument arrangements, the panel.being provided with the necessary lightingfixtures. This type of panel:has proved to be disadvantageous both in production and actual use.Thus, in production, greatcare must be taken in tailoring the cutouts toproperly fit the individual instruments or the entire .panel will .bepractically useless. Furthermore, a different :cover panel is requiredfor each specific arrangement of the instruments on the mounting panel.

.In operation, if it is desired to rearrange the instruments 1011 themounting panel, a new cover panel will be necessary. 'Inaddition,continued use of the single cover panel has .often resulted in buckling.of the panel thereby disrupting the desired distribution of the lightand the efiicient operation.

The present inventors, in application .Serial No. 50,342, filedSeptember 21, .1948, now Patent No. 2,614,205, for Aircraft InstrumentLighting, have proposed one system for obviating the above-mentioned,and other disadvantages of the prior art systems, wherein .an individualcover panel is provided :foreach instrument, this panel having thelighting mean for illuminating :the dial of its associated instrumentmounted thereon.

In operation, the system proposed in the earlier application, althoughovercomin many of the disadvantages of'the prior art, has presentedcertain problems. Firstly, it has been found that the lamp sockets,which extend upwardly beyond the upper surface of the-cover panel of theearlier system have acted as a visual cut-01f of the instrument dial.Secondly, due to the fact that the cover panel is mounted on theinstrument panel on separate screws, much valuable space has beenexpended, anddifficulty has been experienced in mounting the coverpanels over instruments which are inclose proximity-to each other. Inaddition, whenever it is desired --'to remove the instrument from itsmounting, it has been necessary to entirely remove the cover panel.

The present invention proposes to eliminate these and otherdisadvantages by providing a system comprising a mounting base platewhich is mounted directlyover the instrument mounting means, the basePlate .being provided lwithlthe l n in means. and a rcovernanel which ,1is the provision of an individual instrument lighting cover paneloccupying a minimum of space and ofiering a maximum of illumination ofthe-instrument.

Another object is to provide an individual instrument lighting coverpanel which can be secured to the mounting panel by means of theconventional instrument mounting screws.

A further object is to provide an individual instrument lighting coverpanel which may be readilyremoved in a single operation.

Still another object of this invention is the provision of an individualinstrument lighting cover panel which in no way interferes with theoperators visibility of the instrument dial.

Other objects and advantages of the invention will hereinafter becomemore fully apparent from the vfollowing detailed description of theannexeddrawing, wherein:

Fig. 1 is a front elevational View of a,port ion of an instrument boardillustratin an instrument and a preferred embodiment of the lightingsystem of the present invention;

Fig. 2 is afront elevational view-of the "back plate of the ,presentinvention with the lamp and lamp connections mounted thereon;

Fig. 3 is a section taken along the line 3-3 of Fig. 1 looking in thedirections of the arrows;

Fig. 4 is a sectional viewof the; lamp and lamp holder of'Fig. '2;

Fig. 5 is a plan view, partly in section, of the electrical connectorof1Fig.,2; and

Fig. 6 is a section taken on the line 6.-16 of Fig. .1, with certainparts removed, illustrating the illumination of-the instrumentdialaccording tothe present invention.

Referring now to the drawing, wherein like reference charactersdesignatelike or corresponding .partsthroughout the several .views,there is shown :in Fig. 1 a portion H of an instrument board having aninstrument 12 mounted thereon. Mounted over instrument [2 .in a mannerto be described below is the lighting system 13 of the presentinvention, system 13 comprising a cover panel I4 and vaback :plate i5,shown in Referring now to Fig. 2, it is seen that back plate |5 isprovided with a pair of lower apertures l6 and a pair of bossed upperapertures I! through which pass the mounting screws, not shown, of theinstrument whereby mounting of the instrument on the instrument boardwill also simultaneously mount plate l5. Plate I5 is also provided withan internally threaded boss l8 and a pair of integral projecting lugs ISin order to mount panel |4 over plate l5, the mounting bein accomplishedby means of screw 2| and a pair of apertures, not shown, in the upperside surface of panel l4.

Mounted on the upper surface of plate [5 by any suitable means 22 is asplit electrically insulating body 23 having an electrical sleeveconnector 24 passing axially therethrough. As

shown in Fig. 5, connector central section 25 having a pin 26 mountedthere in to which is connected a lead 21 from one terminal of a powersupply, not shown, and a pair of split sleeve end sections 28 in each ofwhich is tightly fitted conducting terminal 29 of lamp socket 3|.

As shown in Fig. 4, each lamp socket 3| comprises a cylindricalinsulating sleeve portion 32, and a relatively smaller cylindricalsleeve portion 33 joined to portion 32 by means of insulating sleeve 34,all the portions of theinsulating sleeve being integral.

Sleeve portion 32 is preferably made of a material translucent to light,such as a material which transmits only red light, although it is clearthat sleeve 32 may be made light transparent or of a material whichtransmits any other color. Socket 3| further comprises a conductingsleev tightly fitting within sleeve portion 32 and integral withterminal 29, which extends through sleeve portions 33 and 34 andoutwardly thereof. The inner surface of connecting sleeve 35 ispreferably made light-reflecting, and substantially one-half of thesurface thereof positioned in front of lamp 36 is cut away in order topermit the passage of light therethrough.

In order to retain lamp 36 in socket 3|, a spring 31 is mounted within acircumferential groove, not designated in sleeve 35, as shown in Fig. 4,a portion of insulating sleeve portion 32 at its outer end being cutaway, as shown in Figs. 2

and 4, to permit easy removal of lamp 36. In its operative position,each socket 3| has its terminal 29 extending into section 28 ofconnector 24, as shown in Fig. 2, the central terminal 38 of lamp 36abutting against upwardly extending bracket 39, mounted on plate |5, tomaintain socket 3| and lamp 36 in fixedposition.

By this arrangement of the sockets and lamps, all of the illuminationfrom lamps 36, including that reflected from the back portion of sleeve35, is directed outwardly through the cut-away portion of sleeve 35 ontothe dial 4| and pointer 42 of instrument I2. In addition, it can be seenthat lamps 36 and their associated sockets 3| are positioned entirelywithin the outline of plate l5, thus eliminating the necessity forexpending much valuable space. By this arrangement, the instruments maybe placed in close proximity on the instrument board, the onlylimitation being the space occupied by the instrument itself.

It is also apparent that by arranging mounting means It and I! for plateI5 in alignment with the mounting means for instrument l2, as shown inFig. 2, additional space is saved. Finally, bymean of positioning theaxes of lamps 36 and sockets 3! parallel to the plane of plate I5, the

24 comprises a solid possibility of visual cut-off of a portion ofinstrument dial 4| is entirely eliminated.

Referring now to Fig. 6, which illustrates the light distributionachieved by the system of the present invention, it can be seen that nolight rays can emerge from the sides of system l3, due to the presenceof upwardly extending flange 43 integrally formed along the outer edgesof plate l5 and cooperating downwardly extending integral flange 44 onpanel |4. Similarly, the upper surface of panel |4 adjacent each oflamps is provided with a vertical portion 45 and an inclined or bevelledportion 46 in order to prevent any of the light rays from reaching theeyes of the observer directly, and to direct the light rays downwardlytoward the instrument dial 4|.

In order to prevent any of the direct rays of light from lamps 36 fromstriking the markings on the peripheral area of dial 4| between ten andtwo o'clock, opposite sides of the upper portion of plate I!) areprovided with projection 48, shown in Fig. 2, which, when the system isassembled, are in the path of such rays so that only direct light raysof angles equal to or less than that of ray 49 reach glass 41, as shownin Fig. 6. Thus, the only rays striking this area of dial 4| are thosereflected from flange 46 of panel |4.

To prevent rays of light from being reflected upwardly from the bezel ofglass 41 into the eyes of the observer, a flange 5| is provided on thelower surface of plate I5, flange 5| extending into the path of theserays, such as rays 53, as shown in Fig. 6. A flange 52 is provided alongthe lower surface of panel I4, flange 52 serving to trap any of thelight rays directed downwardly toward the lower surface of theinstrument and preventing any rays from impinging upon the top of thenext instrument.

The distance 54 between flange 46 and projection 48 is critical and isso dimensioned that direct rays from lamps 36 can reach glass 41 at nolower than the approximate center thereof, this limit being indicated byray 55 in Fig. 6. It has been found that light rays striking glass 41below this point serve no useful function in lighting dial 4| andpointer 42, but do produce glare by reflection from the surface of glass46. On the other hand, rays reaching glass 46 at points above theapproximate center are refracted through the glass and downwardly towardthe bottom of dial 42.

Experimentation has shown that the system of the present inventionproduces a high degree of uniformity of illumination of the instrumentdial and pointer, eliminates substantially all glare, and utilizes mostefficiently the space and power available for electrical lighting.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention and thatnumerous modifications or alterations may be made therein withoutdeparting from the spirit and the scope of the invention as set forth inthe appended claims.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

1. An individual lighting device for each instrument of an instrumentboard, said device comprising a back plate adapted to fit over the faceof the instrument. means for detachably on opposite horizontally alignedupper corners of said plate, respectively, the axis of each of saidlamps being substantially parallel to the plane of said plate, a coverpanel, means on said plate and said panel for detachably mounting saidpanel over said plate and lamps, and light-impervious means dependingfrom said plate below said lamps for preventing direct rays of lightfrom said lamps from reaching the peripheral area of the dial of theinstrument 60 degrees on each side of a vertical diametrical linethrough the dial.

2. A device according to claim 1, and light impervious means on saidpanel cooperating with the last-mentioned means for preventing rays oflight from said lamps from striking the glass of the instrument belowthe center thereof.

3. A device according to claim 2, in which the front surface of saidcorners and said light impervious means are coplanar.

4. An individual lighting device for each in strument of an instrumentboard, said device comprising a back plate being apertured to fit overthe face of the instrument, means for detachably mounting said plate onthe instrument, a pair of lamps mounted tally aligned upper corners ofsaid plate, respectively, said lamps being positioned between the outerconfines of said plate and said aperture, the axes of each of said lampsbeing substantially parallel to the plane of said plate, said platehaving integral projections extending into said aperture below each ofsaid lamps for preventing direct rays of light from said lamps fromreaching the peripheral area of the dial of the instrument 60 degrees oneach side of a vertical diametrical line a cover panel having a visionopening and being detachably mounted on said plate to constitute afrontal shield for said lamps and plate.

5. A device according to claim 4, and a flange depending from said paneland cooperating with said projections for preventing rays of light fromsaid lamps from striking the glass of the instrument below the centerthereof.

6. A device according to claim 5 in which the front surface of saidcorners and said projections are coplanar.

7. An individual lighting device for each instrument of an instrumentboard, said device comprising a back plate being apertured to fit overthe face of the instrument, means for detachably mounting said plate onthe instrument, a pair of lamp sockets mounted on opposite horizontallyaligned upper corners of said plate, respectively, said sockets beingpositioned between the outer confines of said plate and said aperture, alamp mounted in each of said sockets, the axes of each of said socketsbeing substantially parallel to the plane of said plate, each of saidsockets comprising a light-impervious member surrounding said lamp andhaving a lower portion thereof cut away for emitting rays of lighttherethrough, said plate having integral projections extending into saidaperture below each of said cut away portions for preventing direct raysof light from said lamps from reaching the peripheral area of the dialof the instrument 60 degrees on each side of a vertical diametrical linethrough the dial, and a cover panel having a vision opening and beingdetachthrough the dial, and

6 ably mounted on said plate to constitute a frontal shield for saidsockets and plate.

8. A device according to claim 1, in which the front surface of saidcorners and said lightimpervious means are coplanar.

9. A device according to claim 4, in which the front surface of saidcorners and said projections are coplanar.

10. A device according to claim '7 in which the front surface of saidcorners and said projections are coplanar.

11. An individual lighting device for each instrument of an instrumentboard, said device comprising a back plate having a front planar surfacebeing apertured to fit over the face of the instrument, the upperportion of said plate aperture being arcuate at least through an angleextending 60 degrees on each side of a vertical diametrical line throughthe aperture, means for mounting said plate on the instrument, a pair oflamps mounted on opposite horizontally aligned upper corners of saidplate, respectively, said lamps being positioned between the outerconfines of said plate and said aperture, the axes of each of said lampsbeing substantially parallel to the plane of said plate, said platehaving integral projections depending therefrom and coplanar therewithand extending into said aperture below each of said lamps for preventingdirect rays OI light from said lamps from reaching the peripheral areaof the dial of the instrument 60 degrees on each side of a verticaldiametrical line through the dial, and a cover panel having a visionopening and being detachably mounted on said plate to constitute afrontal shield for said lamps and plate.

12. A device according to claim 11, in which a flange depends from saidpanel and cooperates with said projections for preventing rays of lightfrom said lamps from striking the glass of the instrument below thecenter thereof.

13. An individual lighting device for each instrument of an instrumentboard, said device comprising a back plate having a front planar surfacebeing apertured to fit over the face of the instrument, the upperportion of said plate aperture being arcuate at least through an angleextending 60 degrees on each side of a vertical diametrical line throughthe aperture, means for detachably mounting said plate on theinstrument, a pair of lamp sockets mounted on opposite horizontallyaligned upper corners of said plate, respectively, said sockets beingpositioned between the outer confines of said plate and said aperture, alamp mounted in each of said sockets, the axes of each of said socketsbeing substantially parallel to the plane of said plate, each of saidsockets comprises a lightimpervious member surrounding said lamp andhaving a lower portion thereof cut away for emitting rays of lighttherethrough, said plate having projections coplanar therewith andextending into said aperture below each of said cut away portions forpreventing direct rays of light from said lamps from reaching theperipheral area of the dial of the instrument 60 degrees on each side ofa vertical diametrical line through the dial, and a vision opening andbeing on said plate to constitute said sockets and plate.

JOHN M. ROPER.

THOMAS O. TWIST.

a frontal shield for (References on following page) depending therefromand.

7 References Cited in the file of this patent UNITED STATES PATENTSNumber Name Date 1,137,773 Marsden May 4, 1915 1,263,075 Knaufi Apr. 16,1918 1,620,328 Dingman Mar. 8, 1927 1,642,187 Young Sept. 13, 19271,668,522 Zubaty May 1, 1928 1,701,413 Lewellen Feb. 5, 1929 1,786,768Moorhouse Dec. 30, 1930 10 2,140,972 Rylsky Dec. 20, 1938 Number NumberName Date Trautner Dec. 20, 1938 Kollsman May 28, 1940 Carbonara. Nov.18, 1941 Hallman Dec. 16, 1947 Suwa. June 14, 1949 Maynard May 9, 1950FOREIGN PATENTS Country Date Italy Aug. 5, 1939

